KROHNE OPTISONIC 7060 EN - Manual (Page 45)

OPTISONIC 7060
Electrical & mechanical installation manual 730962.31.00 page 45 of 52
Overview of the typical values
Parameter Standard value Error Comments
Deviation from the
theoretical velocity of
sound less than ± 0.3 % Greater than ± 0.3 % When calculating the
theoretical velocity of
sound, you must take
special care to ensure
that the gas
composition, pressure
and, in particular, the
temperature are the
same as at the
measuring location
when the log was
recorded. Velocity of sound
The differences
between the velocities
of sound in the paths
should not be greater
than ± 1.5 m/s. Greater than ± 1.5 m/s Temperature
stratification can occur
with low flow rates.
Signal-to-noise ratio ~20 dB
This depends on the
nominal width of the
meter body and the
current process
pressure. Permanently less than
10 dB Possible sources of
interference include
electrical noise caused
by bad contacts on the
connectors or sources
of acoustic interference,
such as control valves
or very high flow
velocities.
Receiving sensitivity /
AGC level This depends on the
nominal width of the
meter body and the
current process
pressure. Significant deviations
(greater than 50%) from
the historical data with
similar process
pressures The receiving sensitivity
is inversely proportional
to the process
pressure: when the
pressure doubles, the
sensitivity halves.
Number of rejected
measurements < 5 % with zero point
< 35 % with flow Permanently greater
than 50%
Deviations from the standard values specified in the table can indicate a malfunction. In
addition to diagnosing the error (as described in Section 6), you can also create a diagnosis
and status log and send this to KROHNE for analysis (see software manual).